Dial for electrical instruments



May 29, 1923.

V. H. MEYER DIAL FOR ELECTRICAL INSTRUMENTS Filed July 31-; 1922 v I h t.

DIAL FOR ELECTRICAL INSTRUMENTS.

Application filed July 31, 1922. Serial No. 578,602

To all whom it may concern:

Be it known that I, VERNON H. MEYER,

- a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements inDials for Electrical Instruments, of which the following is a specification.

This invention relates to a dial adapted for use on electrical instruments, particularly condensers or other instruments used in radio work. These dials, so called, are attached to a spindle or shaft controlling a movable part of the instrument, for the purpose of turning the shaft. In condensers or tuninginstruments a very fine adjustment is often necessary, and it is sometimes impossible to obtain this fine adjustment by means of the dial of the ordinary type, Which is provided with a knob by which the dial is turned.

The present invention modifies the diat by providing a'raised flange, against which the fingers of the hand may be placed. and the hand may be rested if necessary on the instrument and then a very fine adjustment obtained by slight movement of the fingers, whereas when an ordinary knob is grasped it is impossible to control the turn of the dial with a desirable delicacy.

The dial is illustrated in the accompanying drawings in which Figure l is aplan thereof. Fig. 2 is a cross section. Figs. 25 and 4 are similar views of a modification.

The dial consists of a bottom plate (Band a knob 7 connected to the plate by a stem 8 which is bored as indicated at 9 to receive the shaft (not shown) of the instrument to which the dial is applied. The knob is notched as usual as indicated at 10. These parts are old. i a

The new feature consists of a raised cironlar flange 11 pro eetlng from the base plate 6, near theouter edge thereof, and this flange is knurled on the outer edge indicated at.'12. The dial will have the usual series of index marks and divisions as shown in F 1.

In using the dial thus described it may be'turned to coarse adjustment by means of the knob. Then the fingers may be rested on the knurled edge of the flange ll and a very slight creeping motion or delicate adjustment may be given by slight movement of the fingers, so that the instrument may be adjusted with desirable precision. As stated, the dial will be found useful o radio instruments of known types.

In the modified form shown in Figs. 3 and 4, instead of the raised flange 11 l provide the bottom plate li'with a plurality of pins or projections 14' extending outwardly from the face thereof. This form is capable of being used in the same way. That is, the hand of the operator can be rested on the instrun'ient board while he presses with his fingers against one of the posts 14. thereby permitting a very delicate shift or adjustment of the instrun'ient being made. I

I claim as my invention:

1. dial of the kind described, comprising a base provided with a knob, and a circular knurled flange projecting from the base and extending around the same near the outer edge thereof.

2. A dial of the kind described provided with a knob and with studs near its outer edge adapted to receive finger pressure.

In testimony whereof, I aiiix my signature in presence of two witnesses.

VERNON ll. MEYER.

llitn'esses JoI-IN A. BoMMHARD'r, EDWARD I. HOBDAY. 

